The invention is concerned with a double walled insulated container for storing low boiling liquified gases with an inner container and an outer container of aluminum or steel as well as a neck tube, consisting of fiberglass reinforced plastic, for connecting the two containers.
Doubled walled insulated containers for low boiling liquified gases are increasingly made of aluminum since such containers are considerably lighter then those made of steel. Between the inner container and the outer container, there is a high grade insulation and, likewise, the joint between the inner container and the outer container, the so-called neck tube must have good thermal insulation.
For this purpose, neck tubes made of plastic, especially fiberglass reinforced epoxy resin, have performed well. High requirements are expected relating to the joint between the neck tube and the containers. This joint must be mechanically stable and completely gas tight.
Aside from this, this joint should not be too expensive. Known joints are designed as screw joints or crimp joints with which an adhesive can additionally be applied in order to achieve airtightness. Such a joint is disclosed, for example, by GB PS No. 1 125 588. A joint is known from EP-0S No. 0 098 766, according to which the neck tube is connected to the containers solely by adhesion. For this purpose, the containers' openings are cone shaped and, together with the cylindrical neck tube, form a gap which can be filled with adhesive. This joint cannot be satisfactory in all cases since precise glued joint requires that it be smooth, thin and even and it contains no gas or air inclusions. Aside from this, the glued joint should not be subjected to tension. In the case of known joints, such tensions cannot be avoided, at least during transport. Screw joint or crimp joints which are satisfactory as far as sealing and mechanical stability are concerned are fairly expensive to manufacture.